Chapter 5 - Interaction Design

Abstract

This chapter discusses issues relevant in designing interaction sequences for interactive systems. The goal of interaction design is to specify the mechanisms for accessing and manipulating task information. As in all aspects of system development, designers have many options to choose from in designing a user interaction. Their goal is to compose and sequence user-system exchanges in a way that is intuitive, fluid, and pleasant for the task at hand. Doing this depends on understanding the details of the usage situation. Norman's Gulf of Execution provides an overarching framework for understanding the planning and execution of interaction sequences. Giving the user control is important in an interaction design, but this may come with an increase in task management. Common interaction sequences should be amenable to optimization through good defaults, fast paths, or custom creation of macros. Task decomposition through menu selection is a powerful technique for simplifying and guiding plan development, but can backfire if the decomposition does not match the user's mental model of the task. All systems should support undo sequences, but an effective undo scheme requires an analysis of how users think about their behavior, so that it reverses actions in predictable ways. During interaction design, many details will be predetermined by the software packages supporting a development team. These packages should be carefully examined for interaction options and associated effects on planning and execution. The use of storyboards as a detailed analysis technique was also illustrated.